Investigation On The Power Frequency Electromagnetic And Transmitted Power Of AC1000kv Transmission Lines And Influencing Factors

In order to further satisfy the nation’s growing power demand, our country willcomprehensively promote the construction of ultra-high voltage ac/dc powertransmission network during “12th Five-year” period. Along with the development ofUHV transmission line construction, many new technical problems have arisen, and theimpact of power frequency electromagnetic field of transmission lines on theenvironment has been paid increasingly attention. Therefore, the aim of this paper is tostudy the power frequency electromagnetic environment of1000kV ac transmission lineas well as its transportation power. The power frequency electromagnetic field of thetransmission line in the3dimension space is calculated and analyzed, and efficiency ofpower transfer is analyzed from electromagnetic point of view. Then, various factors onits influence are studied. The main studying contents of this paper are as follows:①The2D and3D space power-frequency electric field of1000kV transmissionline are calculated by using the charge simulation method, and the impacts of sag onelectric field of transmission line are compared and analyzed. The results show that theeffects of the1000kV transmission lines sag on the power frequency electric field aremore obvious than the low voltage level transmission lines. For the1000transmissionlines of the500m span, at the maximum sag,the power frequency electric field is9.865kV/m, at the distance of maximum sag100m, the power frequency electric field is5.828kV/m. By the comparison of the two-dimensional space electric field, the resultsshow that it has errors using the two-dimensional model to calculate the transmissionlines power frequency electric field.②Based on Biot-Savart Law, Calculated the three-dimensional magnetic fieldsof1000kV transmission lines, and were compared with two-dimensional powerfrequency magnetic fields, Obtained with the power frequency electric field to the sameconclusions, that the impact of the sagging in the magnetic field is relatively large,two-dimensional model has errors.③Studied the1000kV transmission lines split spacing, phase spacing, wireheight, loop phase sequence parameters on the power frequency electric and magneticfields of the influencing rule. The results show that the split spacing, phase sequencearrangement have a significant effect on the electric field, wire height and the phasesequence arrangement have a significant effect on the magnetic field. ④Studied the calculation method of the three-dimensional Poynting vector,analyzed the conveying power of the1000kV transmission lines from the angle of thePoynting vector. Studied the influencing rule of the split spacing, the phase spacing,transmission lines arrangements, etc. on the energy transmission of power lines, theresults show that the phase spacing has a relatively large effect on the total transmissionpower of the1000kV transmission line, under the premise of ensuring the insulationsafety,1000kV transmission lines conveying power can be provided by reducing thephase spacing.